All plants

Cauliflower

Brassica oleracea var. botrytis

Brassicaceae · cabbage family

Matures
80–110 days
Harvest
Once · Annual
Sun
6–8+ hrs
Spacing
18–24 in
Botanical engraving of Cauliflower

Planting window

When to sow, by microclimate — foggier blocks run a different calendar than sunnier ones.

JanFebMarAprMayJun
Foggy◐●●●●●
Sunny●●◐
JulAugSepOctNovDec
Foggy●●●◐
Sunny●●●
Well-suitedMarginalNot suited

Sunlight

How well it does at each level of direct sun per day.

<2 hrsNot suited
2–4 hrsNot suited
4–6 hrsMarginal
6–8 hrsWell-suited
8+ hrsWell-suited
Well-suitedMarginalNot suited

Soil depth

Root room it needs — useful for sizing raised beds and containers.

6–10"Not suited
10–15"Marginal
15–18"Well-suited
18–24"Well-suited
Well-suitedMarginalNot suited

Spacing

Room each plant needs — along the row and between rows — for sizing beds.

In-row
18–24 in
Between rows
24 in

Growth habit

The shape it makes in the bed and how tall it gets — what tells you whether to give it a trellis, a stake, or just room.

Habit
Upright
Mature height
1–2.5 ft

Stands on its own; the tallest types appreciate a stake in wind.

How to start it

Sow it where it grows, or raise it under cover and set it out — and how far ahead to start the seedlings if it's the latter.

Usually
Transplant
Start indoors
6 weeks ahead
Direct-sowMarginal
TransplantWell-suited

Started under cover, then set out as a seedling.

Well-suitedMarginalNot suited

Getting started

How it goes in the ground — how deep to sow or set it, and the soil temperature it needs to wake up. The cold-soil floor is the real limiter for direct-sowing in a foggy SF spring.

Started from
From seed
Ideal soil temp
65–85°F
Sow depth
0.5 in
Time to emerge
5–10 days

Germinates between 40–95°F; happiest around 65–85°F.

30°F110°F
IdealWorkable

Pests & diseases

What tends to trouble this crop — what it is, what you'll see, and what to do about it, least-toxic first.

Pests11

Aphids
What it is
Aphids have soft pear-shaped bodies with long legs and antennae and may be green, yellow, brown, red, or black depending on the species and the plants they feed on. A few species appear waxy or woolly due to the secretion of a waxy white or gray substance over their body surface.
What you'll see
Low to moderate numbers of leaf-feeding aphids aren't usually damaging in gardens or on trees. However, large populations can turn leaves yellow and stunt shoots; aphids can also produce large quantities of a sticky exudate known as honeydew, which often turns black with the growth of a sooty mold fungus.
What to do
Before planting vegetables, check surrounding areas for sources of aphids and remove these sources. On the other hand, these aphid-infested weeds can sometimes provide an early source of aphid natural enemies.
Source
Armyworms
What it is
Armyworm larvae feed in groups, which distinguishes them from other vegetable pests such as corn earworms and loopers. Markings on newly hatched armyworms are usually hard to distinguish from those of other caterpillars; older larvae have distinct lengthwise stripes.
What you'll see
Armyworms may feed on the crowns of seedlings. On larger plants, armyworm caterpillars skeletonize leaves.
What to do
Handpick. Virus diseases, parasites (Hyposoter and Trichogramma), and general predators may be effective on caterpillars.
Source
Cutworms
What it is
Cutworms are dull brown caterpillars ranging in length from 1 to 2 inches when fully grown. They curl into a C-shape when disturbed.
What you'll see
Cutworms feed on blossoms and leaves of many ornamental plants and attack most garden crops. They clip off seedling stems near or just below the soil level.
What to do
Cutworms are pests mainly in the spring. Destroy crop residues; keep garden weed-free in winter.
Source
Earwigs
What it is
The adult earwig is readily identified by a pair of prominent appendages that resemble forceps at the tail end of its body. Used for defense, the forceps are somewhat curved in the male but straighter in the female.
What you'll see
European earwigs feed on a variety of dead and living organisms, including insects, mites, and growing shoots of plants. They are voracious feeders on soft-bodied insects such as aphids and insect eggs and can exert significant biological control under some circumstances.
What to do
Management of earwigs requires an integrated program that takes advantage of their habitat preferences. Initiate a regular trapping program.
Source
Flea Beetles
What it is
Their small size, enlarged back legs, characteristic shot-hole damage, and habit of jumping when disturbed make flea beetles easy to identify. There are numerous flea beetle species.
What you'll see
Adults feed mostly on leaves, leaving tiny pits or small holes at their feeding sites. Flea beetles feeding together can cover leaves with bleached, pitted areas or ragged holes.
What to do
Remove debris in the fall to remove any overwintering beetles. Reflective mulches applied very soon after planting and before plants become infected can be helpful.
Source
Harlequin Bug
What it is
Harlequin bugs can be confused with Bagrada bugs, an invasive species, but are much larger and lack the white markings characteristic of Bagrada bugs. Harlequin bugs may also be confused with stink bugs.
What you'll see
Harlequin bugs suck fluids from plant tissue. They leave yellow or white blotches on areas of leaves where they have been feeding; heavy infestations can cause plants to wilt, turn brown, and die.
What to do
Handpick bugs or their eggs. Destroy old cole crop plants and mustards because they provide breeding areas.
Source
Loopers
What it is
Loopers are green caterpillars with several white stripes down their backs. They arch their backs as they crawl, this looping movement giving them their name.
What you'll see
Loopers eat irregular holes in leaves, most often older leaves. They may also bore holes in lettuce and cabbage heads or damage fruit.
What to do
Handpick. Apply Bacillus thuringiensis or spinosad; they are effective against loopers, especially when caterpillars are small.
Source
Snails and Slugs
What you'll see
Snails and slugs feed on a variety of living plants and on decaying plant matter. They create irregular holes with smooth edges on leaves and flowers by scraping with their rasp-like tongues.
What to do
It will not be possible to eliminate some shelters, such as low ledges on fences, the undersides of wooden decks, and water meter boxes, so make a regular practice of trapping and removing snails and slugs from these areas. The survivors congregate in the remaining shelters, where you can more easily locate and remove them.
Source
Thrips
What it is
Most adult thrips are elongate, slender, minute (less than 1/20 inch long), and have long fringes on the margins of both pairs of their long, narrow wings. Immatures (called larvae or nymphs) are oblong or slender and elongate and lack wings.
What you'll see
Thrips feeding on plants can damage fruit, leaves, and shoots and very noticeably affect plants’ cosmetic appearance. However, thrips rarely kill or threaten the survival of trees and shrubs.
What to do
Thrips species that feed on many different plant species often move into gardens and landscapes when plants in weedy areas or grasslands begin to dry in spring or summer. Avoid planting susceptible plants next to these areas, and control nearby weeds that are alternate hosts of pest thrips.
Source
Vegetable Leafminers
What it is
Adult leafminers are small, active, black flies often with a prominent yellow triangle between the bases of the wings. The head behind the eyes is mostly black.
What you'll see
Leafminers attack many different vegetable and flower hosts, including cole crops, cucurbits, tomatoes, peas, beans, aster, begonia, dahlia, impatiens, lily, marigold, petunia, and verbena. Adult female leafminers puncture leaves and sometimes petals to feed on exuding sap.
What to do
Leafminers rarely require treatment in gardens. Clip off and remove older infested leaves.
Source
Whiteflies
What you'll see
Whiteflies use their piercing, needlelike mouthparts to suck sap from phloem, the food-conducting tissues in plant stems and leaves. Large populations can cause leaves to turn yellow, appear dry, or fall off plants.
What to do
Whiteflies have many natural enemies, and outbreaks frequently occur when these natural enemies have been disturbed or destroyed by pesticides, dust buildup, or other factors. General predators include lacewings, bigeyed bugs, and minute pirate bugs.
Source

Diseases5

Bacterial Leafspot of Cole Crops
What you'll see
Infections of bacterial leafspot start as small, dark specks on leaves. As the disease develops, numerous water-soaked leafspots appear.
What to do
Bacterial leafspot occurs primarily in cooler regions such as in coastal areas. Avoid sprinkler irrigation.
Source
Bacterial Soft Rot of Cole Crops
What you'll see
Early symptoms of bacerial soft rot include small water-soaked areas that later expand causing the tissue to become soft and mushy. A strong odor may be apparent.
What to do
The bacteria that causes bacterial soft rot enters plants through wounds caused by insects or mechanical means. Avoid sprinkler irrigation.
Source
Downy Mildew on Cole Crops
What it is
Downy mildew gets its name from the downy masses of spores it produces on the undersides of affected leaves. These downy growths initially may be confused with those of powdery mildew.
What you'll see
Infections of downy mildew begin as irregular yellow patches on leaves; these chlorotic lesions later turn brown. If conditions are favorable, white fluffy growth of the fungus develops on the undersides of leaves.
What to do
The best way to prevent downy mildew is to avoid the environmental conditions that favor it. Destroy infected crop debris and susceptible related weeds before planting a new crop.
Source
Phytophthora Root Rot on Cole Crops
What you'll see
The external surfaces and internal tissues of roots infected with Phytophthora are dark in color and are rotted. Leaves, especially older ones, turn purple red and wilt.
What to do
Phytophthora root rot usually occurs only if cole crops are planted in poorly drained, fine-textured soils that are kept overly wet. Irrigation should be carefully monitored to avoid excessively wet soil conditions.
Source
Verticillium Wilt on Cole Crops
What you'll see
The older, lower leaves of plants infected with Verticillium wilt turn yellow and wilt. Yellowing generally develops between major veins of leaves.
What to do
Verticillium wilt is usually a minor problem on cole crops. In coastal areas it may be more of a problem, especially on cauliflower.
Source

Sources

Every figure above is backed by these.